1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___BIT_BIT_FLOOR_H
10#define _LIBCPP___BIT_BIT_FLOOR_H
11
12#include <__bit/bit_log2.h>
13#include <__concepts/arithmetic.h>
14#include <__config>
15#include <limits>
16
17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18# pragma GCC system_header
19#endif
20
21_LIBCPP_BEGIN_NAMESPACE_STD
22
23#if _LIBCPP_STD_VER >= 20
24
25template <__libcpp_unsigned_integer _Tp>
26[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_floor(_Tp __t) noexcept {
27 return __t == 0 ? 0 : _Tp{1} << std::__bit_log2(__t);
28}
29
30#endif // _LIBCPP_STD_VER >= 20
31
32_LIBCPP_END_NAMESPACE_STD
33
34#endif // _LIBCPP___BIT_BIT_FLOOR_H
35